NANOFILTRATION OF IONIC LIQUID AQUEOUS SOLUTIONS

Identifier:  TFM:180

Handle: https://hdl.handle.net/20.500.11797/TFM180

Authors:  Otalora Garmilla, Javier

Abstract:
NANOFILTRATION OF IONIC LIQUID AQUEOUS SOLUTIONS Javier Otalora Garmilla Master in Nanoscience, Materials and Processes: Chemical Technology at the Frontier (2015/2016) e-mail: javier.otalora@estudiants.urv.cat Supervisors: Dr. Josep Font Capafons Department of Chemical Engineering. Universitat Rovira i Virgili Campus Sescelades, Avinguda Països Catalans, 26, s/n Tarragona, 43007, Spain Abstract. Ionic liquids (ILs) are a promising alternative to replace conventional organic solvents in a wide range of applications, yet recycling and reusing them still remain a challenge. In this context, nanofiltration (NF) can be used to separate and concentrate IL solutions. In this work, we evaluated the use of two commercially available NF membranes (NF270 and NFD) in order to separate Tetrakis(hydroxymethyl)phosphonium chloride solutions with content below 10 wt% using a crossflow nanofiltration unit. The effect of the transmembrane pressure (TMP) and the IL concentration of the feed solution were studied. The experiments showed that NF270 membranes offer higher recovery values and suffer less fouling although they exhibited slightly lower IL rejection than NFD membranes. By using NF270 membranes, it was possible to concentrate IL solutions from 2.2 wt% to 4.5wt% with rejection values over 80%. However, for solutions with higher IL content, the recovery values decreased rapidly due to irreversible fouling effects. On the other hand, we have also demonstrated that is possible to remove the fouling effects by using a 1 wt% EDTA solution and fully restore membrane initial performance.